1. Field of the Invention
The invention relates to a method for isolating a flexible film from a support substrate.
2. Description of the Related Art
Flat panel displays (FPDs) employing a plastic substrate are relatively lighter, thinner and more flexible than other types of FPDs, can be fabricated in large sizes and have become popular.
To fabricate a pixel array substrate of a flexible FPD, a plastic substrate is affixed on a glass substrate, and then the pixel structures (such as thin film transistors) are formed on the plastic substrate. However, one area of technical difficulty in the fabrication process is to efficiently separate the plastic substrate from the glass substrate after the pixel structures are formed.
Specifically, a plastic substrate is apt to tightly bond to a glass substrate since polymeric materials (such as polycarbonate (PC), poly(ethylene terephthalate) (PET), polyimide (PI) etc.) have strong electronegative oxygen atoms, nitrogen atoms, and fluorine atoms which are apt to covalently bond to the hydrogen atoms of the silanol groups of the glass substrate and form hydrogen bonds, as shown in FIG. 1.
U.S. Pat. No. 7,279,401 discloses a method for fabricating a flexible substrate which includes forming a breach between a polymer material layer and a rigid substrate, and injecting a release agent into the breach for isolating the polymer material layer.
TW Patent Appl. No. 200712607 discloses a method for fabricating a flexible substrate which includes forming a release layer on a hard substrate, forming a polymer film on the release layer, and separating the polymer from the hard substrate.